As those skilled in the pertinent art are aware, six telecommunications standard development organizations have joined forces to create the Third Generation Partnership Project (3GPP). The 3GPP in turn has defined standards, called Technical Specifications (TSs), such as Long-Term Evolution (LTE) and Evolved Packet Core (EPC), that act as technology evolution paths for transforming disparate wireless telecommunication standards over time into a single, unified worldwide system for mobile devices, such as smartphones. Consequently, a wide range of powerful mobile telecommunications devices is beginning to appear in the market and gain rapid acceptance.
3GPP wireless devices employ modulation/demodulation circuits, commonly called “modems,” to communicate over wireless carrier frequencies. As sophisticated as these modems are, however, they still use so-called “Attention” or simply “AT” commands, which have been used for decades and employed to control some of the first modems ever developed. Of course, the AT command sets employed with respect to modern modems are far more sophisticated and feature-laden than in the early days, but the general structure of the AT command remains the same: a string of characters beginning with “AT” and followed by other characters specifying the type of AT command and various parameters that may be associated with the type of AT command.
3GPP modems support a command channel, also called an “AT channel,” capable of assuming a command state in which the AT channel is configured to receive AT commands or an online data state in which the AT channel is configured to bear traffic to be communicated wirelessly, e.g., to another modem, in the context of a data connection. According to 3GPP, +CGDATA and D AT commands defined in 3GPP TS 27.007 are employed to command the AT channel to exit the command state and enter the online data state to establish a data connection.